If you checked the switch that engages the pump and you had to do it manualy, then the switch is bad.you can check the switch with a ohms meter.turn on dishwasher,and when it gets to the drain cycle,put the meter leds on the switch contacts,it should read 120volts,it might be a little under that,but not much,maybe 119,118.the other thing it could be,is if you put a new garbage disposal in,there is a plug inside the drain,that the dishwasher hooks to,on disposal,its a knock out plug.you can stick a screwdriver in the drain hole and punch it out.I hope this helps,its really hard to say for sure without being there.Just some obvious pointers.Good luck.If you could explain more to me I think we could figure it out together.Maintrx.